INDOCRYPT 2001, the Second Annual Crypto Conference, is proof of the s- ni?cant amount of enthusiasm generated among Indian as well as International crypto communities. INDOCRYPT 2001 was organized by the Indian Institute of Technology, Madras and the Institute of Mathematical Sciences, also located in Madras (now Chennai). This event was enthusiastically co-sponsored by eAl- traz ConsultingPrivate Ltd, Chennai, Odyssey Technologies Ltd, Chennai, and Shanmuga Arts Science Technology and Research Academy (SASTRA), Th- javur. The Program Committee Co-chair, Prof.C.Pandu Rangan was responsible for local organization and registration. The Program Committee considered 77 papers and selected 31 papers for presentation. These papers were selected on the basis of perceived originality, quality, and relevance to the ?eld of cryptography. The proceedings include the revised version of the accepted papers. Revisions were not checked as to their contents and authors bear full responsibility for the contents of their submissions. The selection of papers is a very challengingand demandingtask. We wish to thank the Program Committee members who did an excellent job in reviewing the submissions in spite of severe time constraints imposed by the tight p- cessingschedule. Each submission was reviewed by at least three referees (only a few by two). The Program Committee was ably assisted by a large number of reviewers in their area of expertise. The list of reviewers has been provided separately. Our thanks go to all of them.